Best wood for rudder

[Phyrexii]

I'm currently working on a design for a transom hung kick up rudder for a 25' boat (specifically a Venture 25). Nominal dimensions are 1 1/2 x 12, with 4' below the waterline, with a true NACA profile. I'm planning on laminating two pieces of 1 x 12 wood together. Also, I am planning to internally weight the lower portion to make it neutrally buoyant by sandwiching a piece of stainless plate in an internal pocket (I might use regular steel, as it should never see the water. If it ever gets wet, then the rudder already failed )

I wish to use readily available lumber (big box store availability). This limits me to oak, maple, poplar, or pine. Of these, which do you think would be the best material to construct the rudder from? Or, would it be worth hunting down another type of wood for the project? I'm leaning toward oak, but I am only moderately familiar with the qualities of wood (I'm more a metal kind of guy ). Thanks!

 

[flynfol]

Clear cedar or mahogany if you want to spend money. Oak is not very rot resistant. Don't leave it in the water either way.

 

[Old Skool Neil]

If you're a metals guy why not make a hollow stainless rudder? That's what Fleming does on their pendulum steering vanes as well as their auxiliary rudder variation for center cockpit boats.

 

[Phyrexii]

If you're a metals guy why not make a hollow stainless rudder? That's what Fleming does on their pendulum steering vanes as well as their auxiliary rudder variation for center cockpit boats.

In this case I want to make it out of wood. Hollow stainless has it's advantages, but I think it will be much easier (and cheaper) for me to make it out of wood, plus I think it looks nicer, IMHO.

I can work with wood, it's just that I'm not fully aware of the specific properties and how they relate to boating (like the fact that oak has a tendency to rot, especially if left submerged - thanks flynfol )

 

[flynfol]

I used this site for my rudder redux.

http://www.jamestowndistributors.co...em/Rudder_Blades_and_Centerboards_000_448.pdf

Here is another.......http://www.jamestowndistributors.co...do?docId=814&title=Building+a+Sailboat+Rudder

 

[Ross]

Carefully select pressure treated southern yellow pine. Resaw it and dress it to the thickness that you want and laminate it with PL premium construction urethane adhesive.

 

[Merlin Clark]

Fir is light, strong, rot resistant, not pricey and readily available.

 

[Ross]

What variety of fir?

 

[Merlin Clark]

I think it's Douglas fir Ross.
Kinda of rare down here, I buy from a yard in Cape Canaveral that used to supply long line, shrimp and scallop boats before they got chased out to make room for cruise ships and tourists.

 

[Ross]

Doug Fir would be a good choice if he can find any high ring count pieces. Most of it is plantation grown and often less than ten rings to the inch. must avoid the pith and of course all sap wood.

 

[kenn]

The stock rudder for our boat was mahogany. Our rudder is 35 years now and has suffered prop bites, edge damage and other indignities, but it is still straight, no splits. When we bought the boat i immediately filled the dings and refinished it and it's been watertight and smooth for 6 seasons. I'm currently touching it up. But it would be an expensive piece of wood today, i bet.

If I had to make a rudder from scratch tomorrow, and it was to have a NACA profile, I would use either marine ply, or synthetic core . Maybe foam with stringers covered with a strong fiberglass skin, like how they make surfboards.

How will you be shaping the rudder to the profile?

 

[Phyrexii]

Kenn,

I have a 30 x 60 CNC milling machine at my disposal, and I am a professional CNC programmer / machinist. It is an easy thing for me to toss a blank on the machine and 3D mill the shape. I estimate it will take about an hour or so of cutting to do both sides.

I have an original mahogany rudder, but it's not 'kick up', and it didn't come with any fittings when I bought my boat. So, rather than cut it up, I took a regular 2 x 12, and quickly made a rudder - and it works fairly well. But now I want to make one that works well and looks nice, and I want to incorporate some of the design features I want internally (I want to add the ballast weight internally, I want a NACA shape for performance, I want internally routed lines or some other kind of mechanism for raising / lowering / releasing upon impact).


(see http://forums.macgregor.sailboatowners.com/showthread.php?p=884816#post884816 for my current setup - ugly, but functional)

 

[Dave Groshong]

For $869 we offer an upgrade, a true air foil shape, lifetime warranty on the blade, includes a beautiful laminated tiller and ready to go sailing right out of the box:

http://shop.macgregorowners.com/detail-rudders.htm?step=2&xkw=Macgregor&skipred=T

If you really want to build your own, I recommend fir, or any decent vertical grained wood, finished with epoxy and paint.

 

[TomY]

The mahogany I buy these days locally in Maine(it's not indiginous-imported) is nice material. I don't know the species but I rebuilt my wooden rudder two years ago. It was built in 1966 and while the bronze drifts all needed replacing, the mahogany stock was as good as new after 50 years of seasonal full time immersion.

The mahogany available today costs me a little less than 10 dollars a board foot. It's nice clear material to work with, machines well and seems to have good rot resistance.

I just glued some up this spring(it takes epoxy very well) and built new hand rails out of it. I would use it to build a rudder today.